The present technology relates to an electrolytic solution including a non-aqueous solvent and an electrolyte salt, to a non-aqueous secondary battery using the electrolytic solution, and to a battery pack, an electric vehicle, an electric power storage system, an electric power tool, and an electronic apparatus that use the non-aqueous secondary battery.
In recent years, various electronic apparatuses such as a mobile phone and a personal digital assistant (PDA) have been widely used, and it has been demanded to further reduce the size and the weight of the electronic apparatuses and to achieve their long life. Accordingly, as an electric power source for the electronic apparatuses, a battery, in particular, a small and light-weight secondary battery capable of providing high energy density has been developed.
In these days, it has been considered to apply such a secondary battery to various other applications in addition to the foregoing electronic apparatuses. Examples of such other applications may include a battery pack attachably and detachably mounted on the electronic apparatuses or the like, an electric vehicle such as an electric automobile, an electric power storage system such as a home electric power server, and an electric power tool such as an electric drill. Further, applications other than the foregoing examples may be adopted.
Secondary batteries utilizing various charge and discharge principles to obtain a battery capacity have been proposed. In particular, a secondary battery utilizing insertion and extraction of an electrode reactant, a secondary battery utilizing precipitation and dissolution of an electrode reactant, and the like have attracted attention, since these secondary batteries provide higher energy density.
The secondary battery includes a cathode, an anode, and an electrolytic solution. The cathode includes a cathode active material layer containing a cathode active material, and the anode includes an anode active material layer containing an anode active material. The electrolytic solution contains a non-aqueous solvent and an electrolyte salt
Since configurations of secondary batteries largely affect battery performance, various studies have been made on the configurations of the secondary batteries for various purposes.
Specifically, in order to improve charge and discharge cycle characteristics and high-temperature conservation characteristics, an alkane amine derivative is added to an electrolytic solution (for example, see Japanese Unexamined Patent Application Publication No. 2011-044352). Examples of the alkane amine derivative may include a compound represented by R4-N—[S(═O)2—R5]2 (where R4 is one of an alkyl group and the like, and R5 is a perfluoroalkyl group). Other examples of the alkane amine derivative may include R6-N—[S(═O)—R7)2] (where R6 is one of an alkyl group and the like, and R7 is a perfluoroalkyl group).
Further, in order to suppress swollenness at the time of conservation at high temperature, a salt is provided on the surface of a cathode active material or the surface of a cathode active material layer (for example, see Japanese Unexamined Patent Application Publication No. 2010-080229). Examples of the salt may include a compound represented by (NR1R2R)(A−)(M+) (where R is one of a hydrogen group, a hydrocarbon group, and the like, R1 and R2 each are one of a hydrocarbon group and the like, A is an acid anion, and M is a metal ion).
In addition thereto, as a related technology, in order to improve voltage resistance and long-time reliability of an electrochemical capacitor, in an electrolytic solution containing an electrolyte salt having quaternary ammonium salt as a main component, the total content of tertiary amine and/or the like is kept to a value equal to or less than a predetermined amount (for example, see Japanese Unexamined Patent Application Publication No. 2000-311839).
Further, in order to obtain an electrolyte salt useful for an electrolytic solution, a method of manufacturing quaternary alkyl ammonium tetrafluoroborate salt has been proposed (for example, see Japanese Unexamined Patent Application Publication No. 2000-226360). In such a manufacturing method, halogenated alkyl is reacted with secondary amine, and thereafter, fluoroboric acid is reacted therewith.